Most of the conventional motor structures include a base, a stator, and a rotor. The base is provided at a center thereof with a bearing cup for receiving a bearing, a retaining ring, a wear-resisting plate or an oil-sealing cap therein. The stator is fitted around the bearing cup. The rotor is provided at a center with a rotary shaft and a permanent magnet. The rotary shaft is rotatably associated with the bearing cup for the stator and the rotor to be assembled together to form a motor structure.
According to the above-described conventional motor structure, the motor operates due to excitation generated by mutual induction between the rotor and the stator. Therefore, the stator is a prerequisite element in the conventional motor structure. The stator in the conventional motor structure includes a plurality of laminated silicon steel sheets and insulating sheets, which is wound around by a coil. The stator with such structure has a fixed height, which prevents the motor structure to reduce its axial height. Further, the permanent magnet on the rotor also has a fixed height. Even if the rotor and the stator are basically parallel with each other in design, this design fails to reduce the axial space of the motor. Therefore, the conventional motor, due to its large axial height, could not be used in a small or narrow space. In brief, the conventional stator and motor have the following disadvantages: (1) there is restriction to the space for mounting them; and (2) they fail to meet the requirement for miniaturization.